Acute feeding effects of Erythrina variegata proteinase inhibitor and Momordica balsamina proteinase inhibitor on the growth and development of Spodoptera frugiperda

Abstract

Proteinase inhibitors (PIs) are widely distributed plant defense proteins against herbivores. Exploiting these proteins in insect control tactics is one of the environmental friendly methods. In this context the present study was undertaken to study the effect of partially purified proteinase inhibitors from Indian coral tree, Erythrina variegata (EvPI) and balsam apple, Momordica balsamina (MbPI) on growth and development of fall armyworm, Spodoptera frugiperda. The three day old larvae were fed with maize leaves treated with EvPI (1, 3 and 6 %) and MbPI (1, 3 and 6 %) and EvPI 6% + MbPI 6% for three days (acute feeding) and untreated leaves until pupation. After feeding, the growth parameters like larval weight, pupal weight, adult weight, larval and adult period were not influenced upon treatments. However, malformations were observed in these treatments and it ranged from 10 to 20 %. There was pupal mortality (12.5 %) in MbPI 6% and combination treatment and adult emergence was reduced upto 12.5 % in these treatments. These results suggest that these treatments did not have great influence on growth and development when fed for short period. Hence, the PIs from E. variegata and M. balsamina shall be used in development of transgenic plants, as transgenic plant will provide opportunities for the larva to continuously feed on thePIs which will affect the growth and development of fall armyworm.